Ketamine

Ketamine is a prescription medication used by physicians for general anesthesia and by veterinarians for animal tranquilization. Unlike other anesthetics, ketamine does not cause loss of consciousness and produces psychedelic or transpersonal effects. Research supports ketamine's effectiveness for off-label treatment of various pain, mental health, and substance use disorders, and it is the only psychedelic drug that can be legally prescribed by U.S. physicians. While widely used legally, ketamine is also used illegally as a recreational drug. According to the Monitoring the Future data, the annual prevalence of ketamine among eighth, 10th, and 12th graders ranges from 1 percent to 1.5 percent. Unlike most drugs used in medicine and for recreation, the typical recreational dose of ketamine is a small fraction of the dose used in medicine. Although legally produced ketamine is occasionally diverted to illegal markets, Mexico is a major supplier of illicit ketamine in the United States according to the U.S. Drug Enforcement Administration.

Ketamine was first synthesized in 1962 and was later patented by Parke-Davis in 1966 as a human anesthetic. During the Vietnam War, ketamine was the most widely used battlefield anesthetic. In 1970 the U.S. Food and Drug Administration (FDA) approved ketamine anesthesia for use with children, adults, and the elderly. Ketamine has been adopted by many hospitals, medical offices, and veterinary clinics because of its rapid onset, proven safety, and short duration of action. Ketamine is also widely used at low doses for treatment of so-called breakthrough pain in patients with acute and chronic pain and for management of neuropathic pain disorder, ischaemic limb pain disorder, refractory cancer pain, and as an adjunct to standard opioid therapy. It also has shown promise as an antidepressant and treatment for alcohol and drug problems. Ketamine is typically snorted, smoked, or administered intramuscularly, but it can also be administered intravenously, orally, or rectally.

Ketamine has minimum life-threatening side effects. Several unintentional overdoses of up to 10 times the amount usually administered have been documented by complete recovery. Clinical studies have failed to detect long-term psychological [Page 451]impairment following its use, including recent studies employing sophisticated neuropsychological tests to examine subtle signs of damage. Considerable ketamine research is occurring at U.S. universities with both normal volunteers and pathological groups like individuals with schizophrenia, substance use, or mood disorders. Studies have demonstrated that ketamine can prevent brain damage in high-risk circumstances due to low blood sugar, low oxygen levels, epileptic seizure, head trauma, heart attack, or stroke.

When abused recreationally in uncontrolled settings like so-called raves, ketamine use can result in significant medical problems, including hyperthermia, excessive sedation, and respiratory depression; this is particularly true when combined with depressants like alcohol, Valium, or gamma hydroxybutyrate. The problems from ketamine misuse support its restriction for research and clinical applications under supervision by qualified professionals.

Ketamine is a rapid-acting, nonbarbiturate, and nonnarcotic agent that has been called a dissociative anesthetic because it creates a sense of disconnection between so-called mind and body. This is quite unlike the properties of conventional anesthetics, which basically extinguish consciousness. Ketamine's dissociative property also creates what can be described as emergence phenomena, which is a nonordinary consciousness state that can be viewed as psychedelic or transpersonal. Users describe profound hallucinations including visual distortions and a lost sense of time, sense, and identity that last from 30 minutes to two hours. Unlike other psychedelic drugs, ketamine has substantial addictive risk. This risk is in part due to its rare pharmacological properties among psychedelic drugs. Ketamine (like DMT and PCP) does not form the acute tolerance characteristic of other drugs with hallucinogenic effects, which makes daily “tripping” impossible. Ketamine, by contrast, does not lose its potency on repeated administration over a short period of time.

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